Metal coordination compound, luminescence device and display apparatus

ABSTRACT

An electroluminescence device having a layer containing a specific metal coordination compound is provided. The metal coordination compound is represented by formula (1) below: 
     ML m L′ n   (1), 
     wherein M is a metal atom of Ir, Pt, Rh or Pd; L and L′ are mutually different bidentate ligands; m is 1, 2 or 3 and n is 0, 1 or 2 with the proviso that m+n is 2 or 3; a partial structure MLm is represented by formula (2) shown below and a partial structure ML′ n  is represented by formula (3) or (4) shown below:  
                 
 
     at least one of the optional substituent(s) of the cyclic groups, and the cyclic groups CyC1 and CyC2 includes a benzofuran structure capable of having a substituent represented by the following formula (5):  
                 
 
     The metal coordination compound having the benzofuran structure is effective in providing high-efficiency luminescence and long-term high luminance.

FIELD OF THE INVENTION AND RELATED ART

[0001] The present invention relates to an organic luminescence device(also called an organic electroluminescence device or organic EL device)for use in a planar light source, a planar display, etc. Particularly,the present invention relates to a novel metal coordination compound anda luminescence device having a high luminescence efficiency and causinglittle change with time by using a metal coordination compoundrepresented by formula (1) appearing hereinafter.

[0002] An old example of organic luminescence device is, e.g., one usingluminescence of a vacuum-deposited anthracene film (Thin Solid Films, 94(1982) 171). In recent years, however, in view of advantages, such aseasiness of providing a large-area device compared with an inorganicluminescence device, and possibility of realizing desired luminescencecolors by development of various new materials and drivability at lowvoltages, an extensive study thereon for device formation as aluminescence device of a high-speed responsiveness and a highefficiency, has been conducted.

[0003] As precisely described in Macromol. Symp. 125, 1-48 (1997), forexample, an organic EL device generally has an organization comprising apair of upper and lower electrodes formed on a transparent substrate,and organic material layers including a luminescence layer disposedbetween the electrodes.

[0004] In the luminescence layer, aluminum quinolinol complexes(inclusive of Alq3 shown hereinafter as a representative example) havingan electron-transporting characteristic and a luminescencecharacteristic, are used for example. In a hole-transporting layer, amaterial having an electron-donative property, such as atriphenyldiamine derivative (inclusive of α-NPD shown hereinafter as arepresentative example), is used for example.

[0005] Such a device shows a current-rectifying characteristic such thatwhen an electric field is applied between the electrodes, holes areinjected from the anode and electrons are injected from the cathode.

[0006] The injected holes and electrons are recombined in theluminescence layer to form excitons, which emit luminescence when theyare transitioned to the ground state.

[0007] In this process, the excited states include a singlet state and atriplet state and a transition from the former to the ground state iscalled fluorescence and a transition from the latter is calledphosphorescence. Materials in theses states are called singlet excitonsand triplet excitons, respectively.

[0008] In most of the organic luminescence devices studied heretofore,fluorescence caused by the transition of a singlet exciton to the groundstate, has been utilized. On the other hand, in recent years, devicesutilizing phosphorescence via triplet excitons have been studied.

[0009] Representative published literature may include:

[0010] Article 1: Improved energy transfer in electrophosphorescentdevice (D. F. O'Brien, et al., Applied Physics Letters, Vol. 74, No. 3,p. 422 (1999)); and

[0011] Article 2: Very high-efficiency green organic light-emittingdevices based on electrophosphorescence (M. A. Baldo, et al., AppliedPhysics Letters, Vol. 75, No. 1, p. 4 (1999)).

[0012] In these articles, a structure including four organic layerssandwiched between the electrodes, and the materials used thereininclude carrier-transporting materials and phosphorescent materials, ofwhich the names and structures are shown below together with theirabbreviations.

[0013] Alq3: aluminum quinolinol complex

[0014] α-NPD:N4,N4′-di-naphthalene-1-yl-N4,N4′-diphenyl-biphenyl-4,4′-diamine

[0015] CBP: 4,4′-N,N′-dicarbazole-biphenyl

[0016] BCP: 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline

[0017] PtOEP: platinum-octaethylporphyrin complex

[0018] Ir(ppy)3: iridium-phenylpyrimidine complex

[0019] The above-mentioned Articles 1 and 2 both have reportedstructures, as exhibiting a high efficiency, including ahole-transporting layer comprising a-NPD, an electron-transporting layercomprising Alq3, an exciton diffusion-preventing layer comprising BCP,and a luminescence layer comprising CBP as a host and ca. 6% of PtOEP orIr(ppy)₃ as a phosphorescent material dispersed in mixture therein.

[0020] Such a phosphorescent material is particularly noted at presentbecause it is expected to provide a high luminescence efficiency inprinciple for the following reasons. More specifically, excitons formedby carrier recombination comprise singlet excitons and triplet excitonsin a probability ratio of 1:3. Conventional organic EL devices haveutilized fluorescence of which the luminescence efficiency is limited toat most 25%. On the other hand, if phosphorescence generated fromtriplet excitons is utilized, an efficiency of at least three times isexpected, and even an efficiency of 100%, i.e., four times, can beexpected in principle, if a transition owing to intersystem crossingfrom a singlet state having a higher energy to a triplet state is takeninto account.

[0021] However, like a fluorescent-type device, such an organicluminescence device utilizing phosphorescence is generally required tobe further improved regarding the deterioration of luminescenceefficiency and device stability.

[0022] The reason of the deterioration has not been fully clarified, butthe present inventors consider as follows based on the mechanism ofphosphorescence.

[0023] In the case where the luminescence layer comprises a hostmaterial having a carrier-transporting function and a phosphorescentguest material, a process of phosphorescence via triplet excitons mayinclude unit processes as follows:

[0024] 1. transportation of electrons and holes within a luminescencelayer,

[0025] 2. formation of host excitons,

[0026] 3. excitation energy transfer between host molecules,

[0027] 4. excitation energy transfer from the host to the guest,

[0028] 5. formation of guest triplet excitons, and

[0029] 6. transition of the guest triplet excitons to the ground stateand phosphorescence.

[0030] Desirable energy transfer in each unit process and luminescenceare caused in competition with various energy deactivation processes.

[0031] Needless to say, a luminescence efficiency of an organicluminescence device is increased by increasing the luminescence quantumyield of a luminescence center material.

[0032] Particularly, in a phosphorescent material, this may beattributable to a life of the triplet excitons which is longer by threeor more digits than the life of a singlet exciton. More specifically,because it is held in a high-energy excited state for a longer period,it is liable to react with surrounding materials and cause polymerformation among the excitons, thus incurring a higher probability ofdeactivation process resulting in a material change or lifedeterioration.

[0033] A luminescence device is desired to exhibit high efficiencyluminescence and show a high stability. Particularly, it is stronglydesired to provide a luminescence material compound which is less liableto cause energy deactivation in a long life of excited energy state andis also chemically stable, thus providing a longer device life.

SUMMARY OF THE INVENTION

[0034] Accordingly, principal objects of the present invention are toprovide a luminescence material which exhibits a high luminescenceefficiency and retains a high luminance for a long period, and alsoprovide a luminescence device and a display apparatus using the same.

[0035] In the present invention, a metal complex is used as aluminescence material, particularly a novel luminescent metal complexcompound comprising iridium as a center metal and a benzofuran structureof formula (5) appearing hereinafter as a part of a ligand or as asubstituent of a ligand.

[0036] More specifically, the present invention provides as aluminescence material a metal coordination compound represented byformula (1) below:

ML_(m)L′_(n)  (1),

[0037] wherein M is a metal atom of Ir, Pt, Rh or Pd; L and L′ aremutually different bidentate ligands; m is 1, 2 or 3 and n is 0, 1 or 2with the proviso that m+n is 2 or 3; a partial structure MLm isrepresented by formula (2) shown below and a partial structure ML′_(n)is represented by formula (3) or (4) shown below:

[0038] wherein CyN1 and CyN2 are each cyclic group capable of having asubstituent, including a nitrogen atom and bonded to the metal atom Mvia the nitrogen atom; CyC1 and CyC2 are each cyclic group capable ofhaving a substituent, including a carbon atom and bonded to the metalatom M via the carbon atom with the proviso that the cyclic group CyN1and the cyclic group CyC1 are bonded to each other via a covalent bondand the cyclic group CyN2 and the cyclic group CyC2 are bonded to eachother via a covalent bond;

[0039] the optional substituent of the cyclic groups is selected from ahalogen atom, cyano group, a nitro group, a trialkylsilyl group of whichthe alkyl groups are independently a linear or branched alkyl grouphaving 1 to 8 carbon atoms, a linear or branched alkyl group having 1 to20 carbon atoms of which the alkyl group can include one ornon-neighboring two or more methylene groups that can be replaced with—O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C—, and the alkyl groupcan include a hydrogen atom that can be optionally replaced with afluorine atom, or an aromatic group capable of having a substituent(that is a halogen atom, a cyano atom, a nitro atom, a linear orbranched alkyl group having 1 to 20 carbon atoms of which the alkylgroup can include one or non-neighboring two or more methylene groupsthat can be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or—C≡C—, and the alkyl group can include a hydrogen atom that can beoptionally replaced with a fluorine atom);

[0040] E and G are independently a linear or branched alkyl group having1 to 20 carbon atoms of which the alkyl group can include a hydrogenatom that can be optionally replaced with a fluorine atom, or anaromatic group capable of having a substituent (that is a halogen atom,a cyano atom, a nitro atom, a trialkylsilyl group of which the alkylgroups are independently a linear or branched alkyl group having 1-8carbon atoms, a linear or branched alkyl group having 1 to 20 carbonatoms of which the alkyl group can include one or non-neighboring two ormore methylene groups that can be replaced with —O—, —S—, —CO—, —CO—O—,—O—CO—, —CH═CH— or —C≡C—, and the alkyl group can include a hydrogenatom that can be optionally replaced with a fluorine atom; and

[0041] at least one of the optional substituent(s) of the cyclic groups,and the cyclic groups CyC1 and CyC2 includes a benzofuran structurecapable of having a substituent represented by the following formula(5):

[0042] wherein the benzofuran structure of the formula (5) is bonded toCyN1, CyN2, CyC1 or CyC2 via a single bond at any one of 2- to7-positions when the benzofuran structure is the optional substituent(s)of the cyclic groups, and the benzofuran structure of the formula (5) isbonded to CyN1 or CyN2 via a single bond at any one of 2- to 7-positionsand bonded to the metal atom M via a single bond at any one of 2- to7-positions when the benzofuran structure is CyC1 or CyC2;

[0043] the optional substituent of the benzofuran structure of theformula (5) is selected from a halogen atom, cyano group, a nitro group,a trialkylsilyl group of which the alkyl groups are independently alinear or branched alkyl group having 1 to 8 carbon atoms, a linear orbranched alkyl group having 1 to 20 carbon atoms of which the alkylgroup can include one or non-neighboring two or more methylene groupsthat can be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or—C≡C—, and the alkyl group can include a hydrogen atom that can beoptionally replaced with a fluorine atom, or an aromatic group capableof having a substituent (that is a halogen atom, a cyano atom, a nitroatom, a linear or branched alkyl group having 1 to 20 carbon atoms ofwhich the alkyl group can include one or non-neighboring two or moremethylene groups that can be replaced with —O—, —S—, —CO—, —CO—O—,—O—CO—, —CH═CH— or —C≡C—, and the alkyl group can include a hydrogenatom that can be optionally replaced with a fluorine atom) with theproviso that an adjacent pair of substituents located at 4- to7-positions of the benzofuran structure of the formula (5) can be bondedto form a cyclic structure.

[0044] Preferred embodiments of the metal coordination compound of theformula (1) according to the present invention include the following:

[0045] A metal coordination compound, wherein n is 0 in the formula (1).

[0046] A metal coordination compound having a partial structure ML′_(n)represented by the formula (3) in the formula (1).

[0047] A metal coordination compound having a partial structure ML′_(n)represented by the formula (4) in the formula (1).

[0048] A metal coordination compound wherein the cyclic groups CyC1 inthe formula (1) and CyC2 in the formula (3) are independently selectedfrom phenyl group, thienyl group, thianaphthyl group, naphthyl group,pyrenyl group, 9-fluorenonyl group, fluorenyl group, dibenzofuranylgroup, dibenzothienyl group, carbazolyl group, or benzofuranyl group, asan aromatic cyclic group capable of having a substituent with theproviso that the aromatic cyclic group can include one or two CH groupsthat can be replaced with a nitrogen atom, particularly selected fromphenyl group or benzofuranyl group.

[0049] A metal coordination compound, wherein the cyclic groups CyN1 inthe formula (2) and CyN2 in the formula (3) are independently selectedfrom pyridyl group, pyridazinyl group, and pyrimidinyl group,particularly pyridyl group, as an aromatic cyclic group capable ofhaving a substituent.

[0050] A metal coordination compound, wherein the cyclic groups CyN1,CyN2, CyC1 and CyC2 are independently non-substituted, or have asubstituent selected from a halogen atom and a linear or branched alkylgroup having 1 to 20 carbon atoms {of which the alkyl group can includeone or non-neighboring two or more methylene groups that can be replacedwith —O—, —S—, —CO—, —CH═CH—, —C≡C—, or a divalent aromatic groupcapable of having a substituent (that is a halogen atom or a linear orbranched alkyl group having 1 to 20 carbon atoms (of which the alkylgroup can include one or non-neighboring two or more methylene groupsthat can be replaced with —O—, and the alkyl group can include ahydrogen atom that can be optionally replaced with a fluorine atom)),and the alkyl group can include a hydrogen atom that can be optionallyreplaced with a fluorine atom}.

[0051] A metal coordination compound, wherein M in the formula (1) isiridium.

[0052] A metal coordination compound represented by the followingformula (6) or (7), particularly the formula (7):

[0053] wherein R₁, R₂, R₃, R′₃ and R₄ are independently

[0054] a hydrogen atom; a fluorine atom; a linear or branched alkylgroup of formula: C_(n)H_(2n+1)- in which n is an integer of 1-20, thealkyl group can include one or non-neighboring two or more methylenegroups that can be replaced with —O— and also can include a hydrogenatom that can be optionally replaced with a fluorine atom; a phenylgroup capable of having a substituent; or a benzofuranyl group capableof having a substituent; the optional substituent of phenyl group andbenzofuranyl group is a fluorine atom or a linear or branched alkylgroup of formula: C_(n)H_(2n+1)—in which n is an integer of 1-20, thealkyl group can include one or non-neighboring two or more methylenegroups that can be replaced with —O— and also can include a hydrogenatom that can be optionally replaced with a fluorine atom.

[0055] The present invention also provides an electroluminescencedevice, comprising: a pair of electrodes disposed on a substrate, and aluminescence unit comprising at least one organic compound disposedbetween the electrodes, wherein the organic compound comprises a metalcoordination compound represented by the formula (1) described above.

[0056] In the luminescence device, a voltage is applied between theelectrodes to emit phosphorescence.

[0057] The present invention further provides a picture displayapparatus, comprising an electroluminescence device described above anda means for supplying electric signals to the electroluminescencedevice.

[0058] These and other objects, features and advantages of the presentinvention will become more apparent upon a consideration of thefollowing description of the preferred embodiments of the presentinvention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0059]FIGS. 1A, 1B and 1C illustrate embodiments of the luminescencedevice according to the present invention, respectively.

[0060]FIG. 2 schematically illustrates a panel structure including an ELdevice and drive means.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0061] Basic structures of organic luminescence (EL) devices formedaccording to the present invention are illustrated in FIGS. 1A, 1B and1C.

[0062] As shown in these figures, an organic luminescence devicegenerally comprises, on a transparent substrate 15, a 50 to 200 nm-thicktransparent electrode 14, a plurality of organic film layers and a metalelectrode 11 formed so as to cover the organic layers.

[0063]FIG. 1A shows an embodiment wherein the organic luminescencedevice comprises a luminescence layer 12 and a hole-transporting layer13. The transparent electrode 14 may comprise ITO, etc., having a largework function so as to facilitate hole injection from the transparentelectrode 14 to the hole-transporting layer 13. The metal electrode 11comprises a metal material having a small work function, such asaluminum, magnesium or alloys of these elements, so as to facilitateelectron injection into the organic luminescence device.

[0064] The luminescence layer 12 comprises a compound (metalcoordination compound) according to the present invention. Thehole-transporting layer 13 may comprise, e.g., a triphenyldiaminederivative, as represented by α-NPD mentioned above, and also a materialhaving an electron-donative property as desired.

[0065] A device organized above exhibits a current-rectifyingcharacteristic, and when an electric field is applied between the metalelectrode 11 as a cathode and the transparent electrode 14 as an anode,electrons are injected from the metal electrode 11 into the luminescencelayer 12, and holes are injected from the transparent electrode 15. Theinjected holes and electrons are recombined in the luminescence layer 12to form excitons having high energy potential, which cause luminescenceduring transition to the ground state. In this instance, thehole-transporting layer 13 functions as an electron-blocking layer toincrease the recombination efficiency at the boundary between theluminescence layer layer 12 and the hole-transporting layer 13, therebyproviding an enhanced luminescence efficiency.

[0066] Further, in the structure of FIG. 1B, an electron-transportinglayer 16 is disposed between the metal electrode 11 and the luminescencelayer 12 in FIG. 1A. As a result, the luminescence function is separatedfrom the functions of electron transportation and hole transportation toprovide a structure exhibiting more effective carrier blocking, thusincreasing the luminescence efficiency. The electron-transporting layer16, may comprise, e.g., an oxadiazole derivative.

[0067]FIG. 1C shows another desirable form of a four-layer structure,including a hole-transporting layer 13, a luminescence layer 12, anexciton diffusion prevention layer 17 and an electron-transporting layer16, successively from the side of the transparent electrode 14 as theanode.

[0068] The luminescence materials used in the present invention are mostsuitably metal coordination compounds represented by the above-mentionedformulae (1) to (5), which are found to cause high-efficiencyluminescence, retain high luminance for a long period and show littledeterioration by current passage.

[0069] The metal coordination compound of the present invention emitsphosphorescence, and its lowest excited state is believed to be an MLCT*(metal-to-ligand charge transfer) excited state or π-π* excited state ina triplet state, and phosphorescence is caused at the time of transitionfrom such a state to the ground state.

[0070] Hereinbelow, methods for measurement of some properties andphysical values described herein for characterizing the luminescencematerial of the present invention will be described.

[0071] (1) Judgment between phosphorescence and fluorescence

[0072] The identification of phosphorescence was effected depending onwhether deactivation with oxygen was caused or not. A solution of asample compound in chloroform after aeration with oxygen or withnitrogen is subjected to photoillumination to cause photo-luminescence.The luminescence is judged to be phosphorescence if almost noluminescence attributable to the compound is observed with respect tothe solution aerated with oxygen but photo-luminescence is confirmedwith respect to the solution aerated with nitrogen. The phosphorescenceof all the compounds of the present invention has been confirmed by thismethod unless otherwise noted specifically.

[0073] (2) Phosphorescence yield (a relative quantum yield, i.e., aratio of an objective sample's quantum yield Φ (sample) to a standardsample's quantum yield Φ (st)) is determined according to the followingformula:

Φ(sample)/Φ(st)=[Sem(sample)/Iabs(sample)]/[Sem(st)/Iabs(st)],

[0074] wherein Iabs(st) denotes an absorption coefficient at anexcitation wavelength of the standard sample; Sem(st), a luminescencespectral areal intensity when excited at the same wavelength;Iabs(sample), an absorption coefficient at an excitation wavelength ofan objective compound; and Sem(sample), a luminescence spectral arealintensity when excited at the same wavelength.

[0075] Phosphorescence yield values described herein are relative valueswith respect to a phosphorescence yield Φ=1 of Ir(ppy)₃ as a standardsample.

[0076] (3) A method of measurement of phosphorescence life is asfollows.

[0077] A sample compound is dissolved in chloroform and spin-coated ontoa quartz substrate in a thickness of ca. 0.1 μm and is exposed topulsative nitrogen laser light at an excitation wavelength of 337 nm atroom temperature by using a luminescence life meter (made by HamamatsuPhotonics K.K.). After completion of the excitation pulses, the decaycharacteristic of luminescence intensity is measured.

[0078] When an initial luminescence intensity is denoted by I₀, aluminescence intensity after t(sec) is expressed according to thefollowing formula with reference to a luminescence life τ(sec):

I=I ₀·exp(−t/τ).

[0079] The luminescence material (metal coordination compound) of thepresent invention exhibited high phosphorescence quantum yields of 0.11to 0.9 and short phosphorescence lives of 0.1 to 40 μsec. A shortphosphorescence life becomes a condition for causing little energydeactivation and exhibiting an enhanced luminescence efficiency. Morespecifically if the phosphorescence life is long, the number of tripletstate molecules maintained for luminescence is increased, and thedeactivation process is liable to occur, thus resulting in a lowerluminescence efficiency particularly at the time of a high-currentdensity. The material of the present invention has a relatively shortphosphorescence life thus exhibiting a high phosphorescence quantumyield, and is therefore suitable as a luminescence material for an ELdevice.

[0080] As a result of various studies of ours, it has been found that anorganic EL device using the metal coordination compound of the formula(1) as a principal luminescence material causes high-efficiencyluminescence, retains high luminance for a long period and shows littledeterioration by current passage.

[0081] In the formula (1) representing the metal coordination compoundof the present invention, n may preferably 0 or 1, more preferably 0.Further, the partial structure ML′n may preferably comprise thebenzofuran structure represented by the above-mentioned formula (5).

[0082] In the present invention, by incorporating the benzofuranstructure of the formula (5) into the metal coordination compound of theformula (1), it becomes possible to control an emission wave-length(particularly to provide a long emission wavelength). The presence ofthe benzofuran structure of the formula (5) is effective in enhancing asolubility of the metal coordination compound of the present inventionin an organic solvent, thus facilitating a purification thereof byrecrystallization or column chromatography. As a result, the metalcoordination compound of the present invention is suitable as aluminescence material for the organic EL device.

[0083] Further, as shown in Examples appearing hereinafter, it has beensubstantiated that the metal coordination compound of the presentinvention exhibited an excellent stability in a continuous currentpassage test. This may be attributable to incorporation of thebenzofuran structure of the formula (5) into the molecular structure ofthe metal coordination compound of the formula (1) according to thepresent invention. More specifically, a change in intermolecularinteraction due to the introduction of the benzofuran structure of theformula (5) allows an intermolecular interaction of the metalcoordination compound with, e.g., a host material to suppress formationof exciton associates causing thermal deactivation, thus reducing aquenching process thereby to improve phosphorescence yield and devicecharacteristics.

[0084] In the case where CyN1 (or CyN2) is benzofranyl group and CyC1(or CyC2) is pyridyl or pyrimidinyl group in the metal coordinationcompound of formula (1) of the present invention, pyridyl or pyrimidinylgroup (CyC1 or CyC2) may preferably have a substituent other than methylgroup, methoxy group, butyl group and fluorine atom when benzofurangroup (CyN1 or CyN2) is not substituted. In another preferred embodimentin the above case, benzofuran group (CyN1 or CyN2) has a substituent,particularly trifluoromethyl group or an aromatic group. In stillanother preferred embodiment in the above case, the metal coordinationcompound has a substituent such as trifluoromethyl group, an aromaticgroup or a cyclized group (e.g., —(CH═CH)₂—).

[0085] The luminescence device according to the present invention maypreferably be an electroluminescence device of the type wherein a layerof the metal coordination compound of the formula (1) is disposedbetween opposing two electrodes and a voltage is applied between theelectrodes to cause luminescence, particularly phosphorescence, as shownin FIGS. 1A, 1B and 1C.

[0086] The luminescence device according to the present invention may beapplicable to devices required to allow energy saving and highluminance, such as those for display apparatus and illuminationapparatus, a light source for printers, and backlight (unit) for aliquid crystal display apparatus. Specifically, in the case of using theluminescence device of the present invention in the display apparatus,it is possible to provide a flat panel display apparatus capable ofexhibiting an excellent energy saving performance, a high visibility anda good lightweight property.

[0087] For the application to a display, a drive system using athin-film transistor (TFT) drive circuit according to an activematrix-scheme may be used. Hereinbelow, an embodiment of using a deviceof the present invention in combination with an active matrix substrateis briefly described with reference to FIG. 2.

[0088]FIG. 2 illustrates an embodiment of panel structure comprising anEL device and drive means. The panel is provided with a scanning signaldriver, a data signal driver and a current supply source which areconnected to gate selection lines, data signal lines and current supplylines, respectively. At each intersection of the gate selection linesand the data signal lines, a display pixel electrode is disposed. Thescanning signal drive sequentially selects the gate selection lines G1,G2, G3 . . . Gn, and in synchronism herewith, picture signals aresupplied from the data signal driver to display a picture (image).

[0089] By driving a display panel including a luminescence layercomprising a luminescence material of the present invention, it becomespossible to provide a display which exhibits a good picture quality andis stable even for a long period display.

[0090] Some synthetic paths for providing a metal coordination compoundrepresented by the above- mentioned formula (1) are illustrated belowwith reference to an iridium coordination compound (m+n 3) for example:

[0091] Other metal coordination compound (M=t, Rh and Pd) can also besynthesized in a similar manner.

[0092] Some specific structural examples of metal coordination compoundsused in the present invention are shown in Tables 1 to Tables 17appearing hereinafter, which are however only representative examplesand are not exhaustive. Pi to Bf6 for CyN1, CyN2, CyC1 and CyC2 shown inTables 1 to 17 represent partial structures shown below.

[0093] Further, aromatic group Ph2 to Bf8 as substituents for CyN1,CyN2, CyC1 and CyC2 shown in Tables 1 to 17 represent partial structuresshown below. TABLE 1 Ph2:

Tn5:

Tn6:

Np3:

Np4:

Tn7:

Tn8:

An:

Pe2:

Pi2:

Pi3:

Qn2:

Ph3:

FL4:

FL5:

FL6:

DBF2:

DBF3:

DBT2:

DBT3:

Bf7:

Bf8:

CyN1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyC1 No M m n CyN1 CyC1 CyC1-R3 CyC1-R4CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 1 Ir 3 0 Pi Bf1 H H — — — — H H H H — — —— 2 Ir 3 0 Pi Bf1 CF₃ H — — — — H H H H — — — — 3 Ir 3 0 Pi Bf1 CF₃ CF₃— — — — H H H H — — — — 4 Ir 3 0 Pi Bf1 H CF₃ — — — — H H H H — — — — 5Ir 3 0 Pi Bf1 H NO₂ — — — — H H H H — — — — 6 Ir 3 0 Pi Bf1 H Cl — — — —H H H H — — — — 7 Ir 3 0 Pi Bf1 H F F — — — — H H H H — — — — 8 Ir 3 0Pi Bf1 H CN — — — — H H H H — — — — 9 Ir 3 0 Pi Bf1 H OCH₃ — — — — H H HH — — — — 10 Ir 3 0 Pi Bf1 H Ph2 H H H H H H H H — — — — 11 Ir 3 0 PiBf1 H Ph2 CF₃ H H H H H H H — — — — 12 Ir 3 0 Pi Bf1 H Ph2 H H F F H H HH — — — — 13 Ir 3 0 Pi Bf1 Ph2 H H H H H H H H H — — — — 14 Ir 3 0 PiBf1 H Np4 H — — — H H H H — — — — 15 Ir 3 0 Pi Bf1 Tn7 H H H — — H H H H— — — — 16 Ir 3 0 Pi Bf1 H C₄H₉ — — — — H H H H — — — — 17 Ir 3 0 Pi Bf1H H — — — — H H OCH₃ H — — — — 18 Ir 3 0 Pi Bf1 H H — — — — H H Cl H — —— — 19 Ir 3 0 Pi Bf1 H H — — — — H H F H — — — — 20 Ir 3 0 Pi Bf1 H H —— — — H H C₈H₁₇ H — — — — 21 Ir 3 0 Pi Bf1 H H — — — — H H NO₂ H — — — —22 Ir 3 0 Pi Bf1 H H — — — — H H Ph2 H H H H H 23 Ir 3 0 Pi Bf1 H H — —— — H H Ph2 H H Si(C₃H₇)₃ H H 24 Ir 3 0 Pi Bf1 Ph2 H — — — — H H Ph2 H HH H H 25 Ir 3 0 Pi Bf1 H H — — — — H H Br H — — — — 26 Ir 3 0 Pi Bf1 H H— — — — H H Bf7 H H H H H 27 Ir 3 0 Pi Bf1 H H — — — — H OC₄H₉ H H — — —— 28 Ir 3 0 Pi Bf1 H Ph2 H OCH₂C₅F₁₁ H H H H H H — — — — 29 Ir 3 0 PiBf1 H H — — — — H Br H H — — — — 30 Ir 3 0 Pi Bf1 H H — — — — HSi(C₈H₁₇)₃ H H — — — — 31 Ir 3 0 Pi Bf2 H H — — — — H H H H — — — —

[0094] TABLE 2 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 No M m n CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 32 Ir 3 0 Pi Bf2 CF₃ H— — — — H H H H — — — — 33 Ir 3 0 Pi Bf2 CF₃ CF₃ — — — — H H H H — — — —34 Ir 3 0 Pi Bf2 H CF₃ — — — — H H H H — — — — 35 Ir 3 0 Pi Bf2 Ph2 H HH H H H H H H — — — — 36 Ir 3 0 Pi Bf2 H Np4 H — — — H H H H — — — — 37Ir 3 0 Pi Bf2 Tn7 H H H — — H H H H — — — — 38 Ir 3 0 Pi Bf2 H C₄H₉ — —— — H H H H — — — — 39 Ir 3 0 Pi Bf2 H H — — — — H H OCH₃ H — — — — 40Ir 3 0 Pi Bf2 H H — — — — H H Ph2 H H Si(C₃H₇)₃ H H 41 Ir 3 0 Pi Bf2 Ph2H H H H H H H Ph2 H H H H H 42 Ir 3 0 Pi Bf2 h Np3 H H H H H H H H — — —— 43 Ir 3 0 Pi Bf2 H Np4 H — — — H H H H H — — — 44 Ir 3 0 Pi Bf2 H Pe2H — — — H H H H — — — — 45 Ir 3 0 Pi Bf2 H Qn2 H H — — H H H H — — — —46 Ir 3 0 Pi Bf2 H An H — — — H H H H — — — — 47 Ir 3 0 Pi Bf2 H Bf7 H HH H H H H H — — — — 48 Ir 3 0 Pi Bf2 Tn5 H H H — — H H H H — — — — 49 Ir3 0 Pi Bf2 H Bf8 H H H H H H H H — — — — 50 Ir 3 0 Pi Bf2 H Tn6 H H — —H H H H — — — — 51 Ir 3 0 Pi Bf3 H H — — — — Ph2 H H H H OCH₃ H H 52 Ir3 0 Pi Bf3 H CF₃ — — — — Ph2 H H H H OCH₃ H H 53 Ir 3 0 Pi Bf3 H CF₃ — —— — Np3 H H H H H — — 54 Ir 3 0 Pi Bf3 H H — — — — H H H H — — — — 55 Ir3 0 Pi Bf3 CF₃ H — — — — C₂H₅ H H H — — — — 56 Ir 3 0 Pi Bf3 CF₃ CF₃ — —— — C₁₀H₂₁ H H H — — — — 57 Ir 3 0 Pi Bf3 H CF₃ — — — — H H H H — — — —58 Ir 3 0 Pi Bf3 H H — — — — Tn5 H H H H H — — 59 Ir 3 0 Pi Bf3 H H — —— — Np3 H H H H H — — 60 Ir 3 0 Pi Bf3 H H — — — — Np4 H H H H — — — 61Ir 3 0 Pi Bf4 H CF₃ — — — — Ph2 H H H H C₆H₁₃ H H

[0095] TABLE 3 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 No M m n CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 62 Ir 3 0 Pi Bf4 H H —— — — C₈H₁₇ H H H — — — — 63 Ir 3 0 Pi Bf4 H H — — — — Ph2 H H H H H H H64 Ir 3 0 Pi Bf4 Np4 H H — — — Ph2 H H H H H H H 65 Ir 3 0 Pi Bf4 FL4 HH H H — Ph2 H H H H H H H 66 Ir 3 0 Pi Bf4 CF₃ CF₃ — — — — C₁₅H₃₁ H H H— — — — 67 Ir 3 0 Pi Bf4 H H — — — — DBT2 H H H H H H — 68 Ir 3 0 Pi Bf4H Bf7 H H H H Ph2 H H H H H H H 69 Ir 3 0 Pi Bf4 H Bf8 H H H H Ph2 H H HH H H H 70 Ir 3 0 Pi Bf4 H Pi3 H H H H Ph2 H H H H H H H 71 Ir 3 0 PiBf5 H CF₃ — — — — Ph2 H H H H C₆H₁₃ H H 72 Ir 3 0 Pi Bf5 H H — — — —C₃H₇ H H H — — — — 73 Ir 3 0 Pi Bf5 CF₃ H — — — — C₂₀H₄₁ H H H — — — —74 Ir 3 0 Pi Ph1 H Bf7 H H H H H H — — — — — — 75 Ir 3 0 Pi Ph1 H Bf7 HH H H H OCH₃ — — — — — — 76 Ir 3 0 Pi Tn1 H Bf7 H H H H H H — — — — — —77 Ir 3 0 Pi Np2 H Bf7 H H H H H H — — — — — — 78 Ir 3 0 Pi Cn1 H Bf7 HH H H H H — — — — — — 79 Ir 3 0 Pi DBT- H Bf7 H H H H 1 H H — — — — — —80 Ir 3 0 Pi Ph1 H Bf8 H H H H H H — — — — — — 81 Ir 3 0 Pi Ph1 H Bf8 HH H H H H — — — — — — 82 Ir 3 0 Pi Tn2 H Bf8 H H H H H H — — — — — — 83Ir 3 0 Pi Np2 H Bf8 H H F H H H — — — — — — 84 Ir 3 0 Pi Cn1 H Bf8 H H HH H H — — — — — — 85 Ir 3 0 Pi Cz H Bf8 H H H H CH3 H — — — — — — 86 Ir3 0 Pr Bf1 H H — — — — H H H H — — — — 87 Ir 3 0 Py1 Bf1 H — — — — — H HH H — — — — 88 Ir 3 0 Py2 Bf1 — H — — — — H H H H — — — — 89 Ir 3 0 PrBf2 H H — — — — H H H H — — — — 90 Ir 3 0 Py1 Bf2 H — — — — — H H H H —— — — 91 Ir 3 0 Py1 Bf2 H — — — — — —(CH═CH)2- H H — — — — 92 Ir 3 0 PiBf1 H H — — — — H —(CH═CH)2- H — — — —

[0096] TABLE 4 CyN1- CyN1 R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 No M m n CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 93 Ir 3 0 Pi Bf1 H H —— — — H H —(CH═CH)2- — — — — 94 Ir 3 0 Pi Bf1 H CF₃ — — — — —(CH═CH)2- HH — — — — 95 Ir 3 0 Pi Bf1 H CF₃ — — — — H —(CH═CH)2- H — — — — 96 Ir 30 Pi Bf1 H CF₃ — — — — H H —(CH═CH)2- — — — — 97 Ir 3 0 Pi Bf1 H Np4 H —— — —(CH═CH)2- H H — — — — 98 Ir 3 0 Pi Bf1 H Ph2 H OCH═CHC₇H₁₅ H H—(CH═CH)2- H H — — — — 99 Ir 3 0 Pi Bf1 H Ph2 H OC≡CC₈H₁₇ H H H—(CH═CH)2- H — — — — 100 Ir 3 0 Pi Bf1 Ph2 H H H H H H H —(CH═CH)2- — —— — 101 Ir 3 0 Pi Bf2 H H — — — — H —(CH═CH)2- H — — — — 102 Ir 3 0 PiBf2 H H — — — — H H —(CH═CH)2- — — — — 103 Ir 3 0 Pi Bf2 H H — — — — H—(CH═CH)2- H — — — — 104 Ir 3 0 Pi Bf2 H Np4 H — — — H H —(CH═CH)2- — —— — 105 Ir 3 0 Pi Bf2 H Ph2 H H F F H H —(CH═CH)2- — — — — 106 Ir 3 0 PiBf1 H Np3 H H — — —(CH═CH)2- H H — — — — 107 Ir 3 0 Pi Bf1 H An H — — —H —(CH═CH)2- H — — — — 108 Ir 3 0 Pi Bf1 H Pe2 H — — — H H —(CH═)2- — —— — 107 Ir 3 0 Pi Bf1 H An H — — — H —(CH═CH)2- H — — — — 109 Ir 3 0 PiBf1 H Cl — — — — —(CH═CH)2- H H — — — — 110 Ir 3 0 Pi Bf1 H Tn8 H H — —H —(CH═CH)2- H — — — — 111 Ir 3 0 Pi Bf1 H Pi3 H H — — H H —(CH═CH)2- —— — — 112 Ir 3 0 Pi Bf1 H Qn2 H H — — —(CH═CH)2- H H — — — — 113 Ir 3 0Pi Bf1 H Ph2 H OCOC₇H₁₅ H H —(CH═CH)2- H H — — — — 114 Ir 3 0 Pi Bf1 HPh2 H CN H H H —(CH═CH)2- H — — — — 115 Ir 3 0 Pi Bf2 H Tn5 H H — — H—(CH═CH)2- H — — — — 116 Ir 3 0 Pi Bf2 H Tn6 H H — — H H —(CH═CH)2- — —— — 117 Ir 3 0 Pi Bf2 H Tn7 H H — — H —(CH═CH)2- H — — — — 118 Ir 3 0 PiBf2 H Pi2 H H — — H H —(CH═CH)2- — — — — 119 Ir 3 0 Pi Bf2 H Ph2 NO₂ H HH H H —(CH═CH)2- — — — — 120 Ir 3 0 Pi Bf2 H DBF3 H H H — H H —(CH═CH)2-— — — — 121 Rh 3 0 Pi Bf1 H H — — — — H H H H — — — — 122 Rh 3 0 Pi Bf1CF₃ H — — — — H H H H — — — —

[0097] TABLE 5 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 No M m n CyN1 Cyc1 R3 R4 R′3 R′4 R5 R6 R7 R8 123 Rh 3 0 Pi Bf1 CF₃CF₃ — — — — H H H H — — — — 124 Rh 3 0 Pi Bf1 H CF₃ — — — — H H H H — —— — 125 Rh 3 0 Pi Bf1 H NO₂ — — — — H H H H — — — — 126 Rh 3 0 Pi Bf1 HCl — — — — H H H H — — — — 127 Rh 3 0 Pi Bf1 H F F — — — — H H H H — — —— 128 Rh 3 0 Pi Bf1 H CN — — — — H H H H — — — — 129 Rh 3 0 Pi Bf1 HOCH₃ — — — — H H H H — — — — 130 Rh 3 0 Pi Bf1 H Ph2 H H H H H H H H — —— — 131 Rh 3 0 Pi Bf2 H H — — — — H H H H — — — — 132 Rh 3 0 Pi Bf-2 CF₃H — — — — H H H H — — — — 133 Rh 3 0 Pi Bf2 CF₃ CF₃ — — — — H H H H — —— — 134 Rh 3 0 Pi Bf2 H CF₃ — — — — H H H H — — — — 135 Rh 3 0 Pi Bf2Ph2 H H H H H H H H H — — — — 136 Rh 3 0 Pi Bf2 H Np4 H — — — H H H H —— — — 137 Rh 3 0 Pi Bf2 Tn7 H H H — — H H H H — — — — 138 Rh 3 0 Pi Bf2H C₄H₉ — — — — H H H H — — — — 139 Rh 3 0 Pi Bf2 H H — — — — H H OCH₃ H— — — — 140 Rh 3 0 Pi Bf2 H H — — — — H H Ph2 H H Si(C₃H₇)₃ H H 141 Pt 20 Pi Bf1 H H — — — — —(CH═CH)2- H H — — — — 142 Pt 2 0 Pi Bf1 H H — — —— H —(CH═CH)2- H — — — — 143 Pt 2 0 Pi Bf1 H H — — — — H H —(CH═CH)2- —— — — 144 Pt 2 0 Pi Bf2 H Tn5 H H — — H —(CH═CH)2- H — — — — 145 Pt 2 0Pi Bf2 H Tn6 H H — — H H —(CH═CH)2- — — — — 146 Pt 2 0 Pi Bf2 H Tn7 H H— — H —(CH═CH)2- H — — — — 147 Pt 2 0 Pi Bf2 H Pi2 H H — — H H —(CH═)2-— — — — 148 Pd 2 0 Pi Bf4 H Pi3 H H — — Ph2 H H H H H H H 149 Pd 2 0 PiBf5 H CF₃ — — — — Ph2 H H H H C₆H₁₃ H H 150 Pd 2 0 Pi Bf1 H H — — — — HH Ph2 H H Si(C₃H₇)₃ H H

[0098] TABLE 6 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 CyN2 CyN2-R1 CyN2-R2 R5 R6 R7R8 CyC2- CyC2- CyC2- CyC2- CyC2 No M m n CyN2 CyC2 R3 R4 R′3 R′4 R5 R6R7 R8 151 Ir 2 1 Pi Bf1 H H — — — — H H H H — — — — Pi Ph`1 H H — — — —H H — — — — — — 152 Ir 2 1 Pi Bf1 CF₃ H — — — — H H H H — — — — Pi Ph1 HH — — — — H H — — — — — — 153 Ir 2 1 Pi Bf1 CF₃ CF₃ — — — — H H H H — —— — Pi Ph1 H H — — — — H H — — — — — — 154 Ir 2 1 Pi Bf1 H CF₃ — — — — HH H H — — — — Pi Ph1 H H — — — — H H — — — — — — 155 Ir 2 1 Pi Bf1 H CF₃— — — — H H H H — — — — Pi Np2 H H — — — — H H — — — — — — 156 Ir 2 1 PiBf1 H Ph2 H H H H H H H H — — — — Pi Ph1 H H — — — — H H — — — — — — 157Ir 2 1 Pi Bf2 H H — — — — H H H H — — — — Pi Ph1 H H — — — — H H — — — —— — 158 Ir 2 1 Pi Bf2 CF₃ H — — — — H H H H — — — — Pi Ph1 H H — — — — HH — — — — — — 159 Ir 2 1 Pi Bf2 CF₃ CF₃ — — — — H H H H — — — — Pi Ph1 HH — — — — H H — — — — — — 160 Ir 2 1 Pi Bf2 H CF₃ — — — — H H H H — — —— Pi Ph1 H H — — — — H H — — — — — — 161 Ir 2 1 Pi Bf2 H CF₃ — — — — H HH H — — — — Pi Ph1 CF₃ H — — — — H H — — — — — —

[0099] TABLE 7 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 CyN2 CyN2-R1 CyN2-R2 R5 R6 R7R8 CyC2- CyC2- CyC2- CyC2- CyC2 No. M m n CyN2 CyC2 R3 R4 R′3 R′4 R5 R6R7 R8 162 Ir 2 1 Pi Bf2 H Ph2 H H H H H H H H — — — — Pi Ph1 H H — — — —H H — — — — — — 163 Ir 2 1 Pi Bf2 Ph2 H H H H H H H H H — — — — Pi Ph1 HH — — — — H H — — — — — — 164 Ir 2 1 Pi Bf2 Tn7 H H H — — H H H H — — —— Pi Ph1 H H — — — — H H — — — — — — 165 Ir 2 1 Pi Bf2 H C₄H₉ — — — — HH H H — — — — Pi Ph1 H H — — — — H H — — — — — — 166 Ir 2 1 Pi Bf2 H H —— — — H H Ph2 H H Si(C₃H₇)₃ H H Pi Ph1 H H — — — — H H — — — — — — 167Ir 2 1 Pi Bf2 Ph2 H H H H H H H Ph2 H H H H H Pi Ph1 H H — — — — H H — —— — — — 168 Ir 2 1 Pi Bf2 H Qn2 H H — — H H H H — — — — Pi Ph1 H H — — —— H H — — — — — — 169 Ir 2 1 Pi Bf2 H Bf7 H H H H H H H H — — — — Pi Ph1H H — — — — H H — — — — — — 170 Ir 2 1 Pi Bf2 H Bf8 H H H H H H H H — —— — Pi Ph1 H H — — — — H H — — — — — — 171 Ir 2 1 Pi Bf3 H H — — — — Ph2H H H H OCH₃ H H Pi Ph1 H H — — — — H H — — — — — — 172 Ir 2 1 Pi Bf3 HCF₃ — — — — Np3 H H H H H — — Pr Ph1 H H — — — — H H — — — — — —

[0100] TABLE 8 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 CyN2 CyC2- CyC2- CyC2- CyC2-CyC2 No M m n CyN2 CyC2 R3 R4 R′3 R′4 R5 R6 R7 R8 173 Ir 2 1 Pi Bf4 HCF₃ — — — — Ph2 H H H H C₆H₁₃ H H Py1 Ph1 H — — — — — H H — — — — — —174 Ir 2 1 Pi Bf4 H Bf7 H H H H Ph2 H H H H H H H Py2 Ph1 — H — — — — HH — — — — — — 175 Ir 2 1 Pi Ph1 H Bf7 H H H H H OCH₃ — — — — — — Pi Ph1H H — — — — H H — — — — — — 176 Ir 2 1 Pi Np2 H Bf7 H H H H H H — — — —— — Pi Ph1 H H — — — — H H — — — — — — 177 Ir 2 1 Pi Tn2 H Bf8 H H H H HH — — — — — — Pi Ph1 H H — — — — H H — — — — — — 178 Ir 2 1 Pi Cn1 H Bf8H H H H H — — — — — — — Pi Ph1 H Np3 H H — — H H — — — — — — 179 Ir 2 1Pi Bf1 H H — — — — —(CH═CH)2- H H — — — — Pi Np2 H H — — — — H H — — — —— — 180 Ir 2 1 Pi Bf1 H H — — — — H —(CH═CH)2- H — — — — Pi Ph1 H CF₃ —— — — H H — — — — — — 181 Ir 2 1 Pi Bf1 H H — — — — H H —(CH═CH)2- — — —— Pi Bf2 H CF₃ — — — — H H H H — — — — 182 Ir 2 1 Pi Bf1 H CF₃ — — — ——(CH═CH)2- H H — — — — Pi Ph1 H CF₃ — — — — H H H — — — — — 183 Ir 2 1Pi Bf1 H CF₃ — — — — H —(CH═CH)2- H — — — — Pi Ph1 H H — — — — H H — — —— — —

[0101] TABLE 9 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 CyN2-R1 CyN2-R2 R5 R6 R7 R8CyC2- CyC2- CyC2- CyC2- CyC2 No M m n CyN2 CyC2 R3 R4 R′3 R′4 R5 R6 R7R8 184 Ir 2 1 Pi Bf1 H CF₃ — — — — H H —(CH═CH)2- — — — — Pi Bf2 H CF₃ —— — — H H H H — — — — 185 Ir 2 1 Pi Bf1 H Np4 H — — — —(CH═CH)2- H H — —— — Pi Ph1 H H — — — — H H — — — — — — 186 Ir 2 1 Pi Bf1 H Ph2 HOCH═CHC₇H₁₅ H H —(CH═CH)2- H H — — — — Pi Ph1 H CF₃ — — — — H H H H — —— — 187 Ir 2 1 Pi Bf1 H Ph2 H OC≡CC₈H₁₇ H H H —(CH═CH)2- H — — — — PiNp2 H H — — — — H H — — — — — — 188 Ir 2 1 Pi Bf1 Ph2 H H H H H H H—(CH═CH)2- — — — — Pi Bf2 H CF₃ — — — — H H H H — — — — 189 Ir 2 1 PiBf2 H H — — — — H —(CH═CH)2- H — — — — Pi Ph1 H H — — — — H H — — — — —— 190 Ir 2 1 Pi Bf2 H H — — — — H H —(CH═CH)2- — — — — Pi Ph1 H H — — —— H H H H — — — — 191 Ir 2 1 Pi Bf2 H H — — — — H —(CH═CH)2- H — — — —Pi Ph1 H H — — — — H H — — — — — — 192 Ir 2 1 Pi Bf2 H Np4 H — — — H H—(CH═CH)2- — — — — Pi Ph1 H CF₃ — — — — H H H H — — — — 193 Ir 2 1 PiBf2 H Ph2 H H F F H H —(CH═CH)2- — — — — Pi Bf1 H Np3 H H — — H H — — —— — — 194 Ir 2 1 Pi Bf1 H Np3 H H — — —(CH═CH)2- H H — — — — Pi Ph1 H H— — — — H H H H — — — —

[0102] TABLE 10 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 CyN2 CyN2-R1 CyN2-R2 R5 R6 R7R8 CyC2- CyC2- CyC2- CyC2- CyC2 No. M m n CyN2 CyC2 R3 R4 R′3 R′4 R5 R6R7 R8 195 Ir 2 1 Pi Bf1 H An H — — — H —(CH═CH)2- H — — — — Pi Bf2 H CF₃— — — — H H H H — — — — 196 Ir 2 1 Pi Bf1 H Pe2 H — — — H H —(CH═CH)2- —— — — Pi Ph1 H CF₃ — — — — H H — — — — — — 197 Ir 2 1 Pi Bf1 H Cl — — —— —(CH═CH)2- H H — — — — Pi Ph1 H H — — — — H H — — — — — — 198 Ir 2 1Pi Bf1 H Tn8 H H — — H —(CH═CH)2- H — — — — Pi Ph1 H H — — — — H H — — —— — — 199 Ir 2 1 Pi Bf1 H Pi3 H H — — H H —(CH═CH)2- — — — — Pi DBT- H H— — — — 1 H H — — — — — — 200 Ir 2 1 Pi Bf1 H Qn2 H H — — —(CH═CH)2- H H— — — — Pi Ph1 H H — — — — H H — — — — — — 201 Ir 2 1 Pi Bf1 H Ph2 HOCOC₇H₁₅ H H —(CH═CH)2- H H — — — — Pi Bf2 H CF₃ — — — — H H H H — — — —202 Ir 2 1 Pi Bf1 H Ph2 H CN H H H —(CH═CH)2- H — — — — Pi Ph1 H CF₃ — —— — H H — — — — — — 203 Rh 2 1 Pi Bf2 H Tn6 H H — — H H —(CH═CH)2- — — —— Pi Ph1 H H — — — — H H — — — — — — 204 Rh 2 1 Pi Bf2 H Ph2 NO₂ H H H HH —(CH═CH)2- — — — — Pi Ph1 H H — — — — H H — — — — — — 205 Rh 2 1 PiBf2 H DBF3 H H H — H H —(CH═CH)2- — — — — Pi Bf2 H CF₃ — — — — H H H H —— — —

[0103] TABLE 11 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 CyN2 CyN2-R1 CyN2-R2 R5 R6 R7R8 CyC2- CyC2- CyC2- CyC2- CyN2 No M m n CyN2 CyC2 R3 R4 R′3 R′4 R5 R6R7 R8 206 Rh 2 1 Pi Bf2 H H — — — — H H Ph2 H H Si(C₃H₇)₃ H H Pi Ph1 H H— — — — H H — — — — — — 207 Rh 2 1 Pi Bf2 Ph2 H H H H H H H Ph2 H H H HH Pi Ph1 H H — — — — H H — — — — — — 208 Rh 2 1 Pi Bf2 H Pe2 H — — — H HH H — — — — Pi Ph1 H CF₃ — — — — H H — — — — — — 209 Rh 2 1 Pi Bf2 H AnH — — — H H H H — — — — Pi Ph1 H H — — — — H H — — — — — — 210 Rh 2 1 PiBf2 H Bf8 H H H H H H H H — — — — Pi Ph1 H H — — — — H H — — — — — — 211Ir 1 2 Pi Bf1 H H — — — — H H H H — — — — Pi Ph1 H H — — — — H H — — — —— — 212 Ir 1 2 Pi Bf1 CF₃ H — — — — H H H H — — — — Pi Ph1 H H — — — — HH — — — — — — 213 Ir 1 2 Pi Bf1 CF₃ CF₃ — — — — H H H H — — — — Pi Ph1 HH — — — — H H — — — — — — 214 Ir 1 2 Pi Bf1 H CF₃ — — — — H H H H — — —— Pi Ph1 H H — — — — H H — — — — — — 215 Ir 1 2 Pi Bf1 H CF₃ — — — — H HH H — — — — Pi Np2 H H — — — — H H — — — — — — 216 Ir 1 2 Pi Bf2 H H — —— — H H H H — — — — Pi Ph1 H H — — — — H H — — — — — —

[0104] TABLE 12 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 CyN2 CyN2-R1 CyN2-R2 R5 R6 R7R8 CyC2- CyC2- CyC2- CyC2- CyC2 No M m n CyN2 CyC2 R3 R4 R′3 R′4 R5 R6R7 R8 217 Ir 1 2 Pi Bf2 CF₃ H — — — — H H H H — — — — Pi Ph1 H H — — — —H H — — — — — — 218 Ir 1 2 Pi Bf2 CF₃ CF₃ — — — — H H H H — — — — Pi Ph1H H — — — — H H — — — — — — 219 Ir 1 2 Pi Bf2 H CF₃ — — — — H H H H — —— — Pi Ph1 H H — — — — H H — — — — — — 220 Ir 1 2 Pi Bf2 H CF₃ — — — — HH H H — — — — Pi Ph1 CF₃ H — — — — H H — — — — — — 221 Ir 1 2 Pi Bf2 HPh2 H H H H H H H H — — — — Pi Ph1 H H — — — — H H — — — — — — 222 Ir 12 Pi Bf1 H H — — — — —(CH═CH)2— H H — — — — Pi Np2 H H — — — — H H — — —— — — 223 Ir 1 2 Pi Bf1 H H — — — — H —(CH═CH)2— H — — — — Pi Ph1 H CF₃— — — — H H — — — — — — 224 Ir 1 2 Pi Bf1 H CF₃ — — — — H H —(CH═CH)2— —— — — Pi Bf2 H CF₃ — — — — H H H H — — — — 225 Ir 1 2 Pi Bf1 H Np4 H — —— —(CH═CH)2— H H — — — — Pi Ph1 H H — — — — H H — — — — — — 226 Ir 1 2Pi Bf1 H Ph2 H OCH═CHC₇H₁₅ H H —(CH═CH)2— H H — — — — Pi Ph1 H CF₃ — — —— H H — — — — — — 227 Ir 1 2 Pi Bf1 H Ph2 H OC≡CC₈H₁₇ H H H —(CH═CH)2— H— — — — Pi Np2 H H — — — — H H — — — — — —

[0105] TABLE 13 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 CyN2 CyN2-R1 CyN2-R2 R5 R6 R7R8 CyC2- CyC2- CyC2- CyC2- CyC2 No. M m n CyN2 CyC2 R3 R4 R′3 R′4 R5 R6R7 R8 228 Ir 1 2 Pi Bf1 H Qn2 H H — — —(CH═CH)2— H H — — — — Pi Ph1 H H— — — — H H — — — — — — 229 Ir 1 2 Pi Bf1 H Ph2 H OCOC₇H₁₅ H H—(CH═CH)2— H H — — — — Pi Bf2 H CF₃ — — — — H H H H — — — — 230 Ir 1 2Pi Bf1 H Ph2 H CN H H H —(CH═CH)2— H — — — — Pi Ph1 H CF₃ — — — — H H —— — — — — 231 Ir 1 2 Pi Bf2 H Tn6 H H — — H H —(CH═CH)2— — — — — Pi Ph1H H — — — — H H — — — — — — 232 Ir 1 2 Pi Bf2 H Ph2 NO₂ H H H H H—(CH═CH)2— — — — — Pi Ph1 H H — — — — H H — — — — — — 233 Ir 1 2 Pi Bf2H DBF3 H H H — H H —(CH═CH)2— — — — — Pi Bf2 H CF₃ — — — — H H H H — — —— 234 Ir 1 2 Pi Bf2 Ph2 H H H H H H H Ph2 H H H H H Pi Ph1 H H — — — — HH — — — — — —

[0106] TABLE 14 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 CyN2 CyN2-R1 CyN2-R2 R5 R6 R7R8 CyC2- CyC2- CyC2- CyC2- CyC2 No M m n CyN2 CyC2 R3 R4 R′3 R′4 R5 R6R7 R8 235 Rh 1 2 Pi Bf2 H Pe2 H — — — H H H H — — — — Pi Ph1 H CF₃ — — —— H H — — — — — — 236 Rh 1 2 Pi Bf2 H An H — — — H H H H — — — — Pi Ph1H H — — — — H H — — — — — — 237 Rh 1 2 Pi Bf2 H Bf8 H H H H H H H H — —— — Pi Ph1 H H — — — — H H — — — — — — 238 Rh 1 2 Pi Bf1 Ph2 H H H H H HH —(CH═CH)2— — — — — Pi Bf2 H CF₃ — — — — H H H H — — — — 239 Pt 1 1 PiBf2 H H — — — — H —(CH═CH)2— H — — — — Pi Ph1 H H — — — — H H — — — — —— 240 Pd 1 1 Pi Bf2 H H — — — — H H —(CH═CH)2— — — — — Pi Ph1 H H — — —— H H — — — — — —

[0107] TABLE 15 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 E E R″ R′′′ R5 R6 R7 R8 G No Mm n G R″ R′′′ R5 R6 R7 R8 241 Ir 2 1 Pi Bf1 H H — — — — H H H H — — — —CH₃ — — — — — — CH₃ — — — — — — 242 Ir 2 1 Pi Bf1 CF₃ H — — — — H H H H— — — — CF₃ — — — — — — CF₃ — — — — — — 243 Ir 2 1 Pi Bf1 CF₃ CF₃ — — —— H H H H — — — — CH₃ — — — — — — CH₃ — — — — — — 244 Ir 2 1 Pi Bf1 HCF₃ — — — — H H H H — — — — Ph2 — — H H H H Ph2 — — H H H H 245 Ir 2 1Pi Bf1 H Ph2 H H H H H H H H — — — — Ph2 — — H C₃H₇ H H Ph2 — — H C₃H₇ HH 246 Ir 2 1 Pi Bf2 H H — — — — H H H H — — — — CH₃ — — — — — — FL5 CH₃CH₃ H H H H 247 Ir 2 1 Pi Bf2 CF₃ H — — — — H H H H — — — — Tn5 — — H H— — Tn5 — — H H — — 248 Ir 2 1 Pi Bf2 CF₃ CF₃ — — — — H H H H — — — —Tn6 — — H H — — Tn6 — — H H 249 Ir 2 1 Pi Bf2 H CF₃ — — — — H H H H — —— — CH₃ — — — — — — CH₃ — — — — — — 250 Ir 2 1 Pi Bf2 H Ph2 H H H H H HH H — — — — CF₃ — — — — — — CF₃ — — — — — — 251 Ir 2 1 Pi Bf2 Ph2 H H HH H H H H H — — — — Np3 — — CH₃O H — — Np3 — — CH₃O H — —

[0108] TABLE 16 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 E E R″ R′′′ R5 R6 R7 R8 G No Mm n G R″ R′′′ R5 R6 R7 R8 252 Ir 2 1 Pi Bf2 Tn7 H H H — — H H H H — — —— Np4 — — F — — — Np4 — — F — — — 253 Ir 2 1 Pi Bf2 H C₄H₉ — — — — H H HH — — — — Tn7 — — CH₃ H — — Tn7 — — CH₃ H — — 254 Ir 2 1 Pi Bf2 H H — —— — H H Ph2 H H Si(C₃H₇)₃ H H Tn8 — — H H — — Tn8 — — H — — 255 Ir 2 1Pi Bf2 Ph2 H H H H H H H Ph2 H H H H H Pe2 — — H — — — Pe2 — — H — — —256 Ir 2 1 Pi Bf2 H Qn2 H H — — H H H H — — — — Pi2 — — H H — Pi2 — — HH — 257 Ir 2 1 Pi Bf2 H Bf7 H H H H H H H H — — — — Pi3 — — CH₃ CH₃ H HPi3 — — CH₃ CH₃ H H 258 Ir 2 1 Pi Bf2 H Bf8 H H H H H H H H — — — — FL4— — H H H — FL4 — — H H H — 259 Ir 2 1 Pi Bf3 H H — — — — Ph2 H H H HOCH₃ H H FL5 C2H5 C2H5 H H H — FL5 (CH2)5Ph3 (CH2)5Ph3 H H H — 260 Ir 21 Pi Bf4 H CF₃ — — — — Ph2 H H H H C₆H₁₃ H H DBF2 — — H H H — DBF2 — — HH H — 261 Ir 2 1 Pi Ph1 H Bf7 H H H H H OCH₃ — — — — — — DBT3 — — H H HH DBT3 — — H H H H 262 Rh 2 1 Pi Bf1 H H — — — — —(CH═CH)2— H H — — — —CH₃ — — — — — — CH₃ — — — — — —

[0109] TABLE 17 CyN1 CyN1-R1 CyN1-R2 R5 R6 R7 R8 CyC1- CyC1- CyC1- CyC1-CyC1 CyN1 CyC1 R3 R4 R′3 R′4 R5 R6 R7 R8 E E R″ R′′′ R5 R6 R7 R8 G No Mm n G R″ R′′′ R5 R6 R7 R8 263 Rh 2 1 Pi Bf1 H H — — — — H —(CH═CH)2— H —— — — CF₃ — — — — — — CF₃ — — — — — — 264 Rh 2 1 Pi Bf1 H H — — — — H H—(CH═CH)2— — — — — Qn2 — — H H — — Qn2 — — H H — — 265 Rh 2 1 Pi Bf2 HCF₃ — — — — H H H H — — — — Np3 — — H H — — Np3 — — H H — — 266 Pt 1 1Pi Bf1 H CF₃ — — — — H H —(CH═CH)2— — — — — CH₃ — — — — — — CH₃ — — — —— — 267 Pt 1 1 Pi Bf1 H Np4 H — — — —(CH═CH)2— H H — — — — CF₃ — — — — —— CF₃ — — — — — — 268 Pd 1 1 Pi Bf1 H Ph2 H OCH═CHC₇H₁₅ H H —(CH═CH)2— HH — — — — CH₃ — — — — — — CH₃ — — — — — — 269 Pd 1 1 Pi Bf2 H CF₃ — — —— H H H H — — — — CF₃ — — — — — — CF₃ — — — — — — 270 Ir 1 2 Pi Bf1 HPh2 H OC≡CC₈H₁₇ H H H —(CH═CH)2— H — — — — CH₃ — — — — — — CH₃ — — — — ——

[0110] In the case where the metal coordination compound of the formula(1) is used as a luminescent material, the metal coordination compoundused singly (as a single luminescent material) or in combination withanother luminescent material (host compound).

[0111] In the latter case, the resultant luminescence material(composition or mixture) may preferably contain the metal coordinationcompound of the formula (1) in an amount of at most 50 wt. %, morepreferably 0.1-20 wt. %. Above 50 wt. %, a resultant luminescencestrength is undesirably be lowered due to quenching with an increasingconcentration in some cases.

[0112] Hereinbelow, the present invention will be described morespecifically based on Examples.

EXAMPLE 1 Synthesis of Example Compound No. 34

[0113]

[0114] In a 100 ml-three-necked flask, 2.80 g (15.4 mM) of2-chloro-5-trifluoromethylpyridine, 2.50 g (15.4 mM) of2-benzofuranylboronic acid, 14 ml of toluene, 7 ml of ethanol and 14 mlof 2M-sodium carbonate aqueous solution were placed and stirred at roomtemperature under nitrogen stream, and 0.55 g (0.48 mM) oftetrakis(triphenylphosphine)palladium (0) was added thereto. Thereafter,reflux under stirring for 4 hours was performed under nitrogen stream.After the reaction, the reaction mixture was cooled on an ice bath andstirred at room temperature after addition of ethyl acetate andsaturated saline water. The organic layer was washed with water anddried with anhydrous magnesium sulfate, and the solvent was removedunder reduced pressure to obtain a residue. The residue was purified byalumina column chromatography (eluent: toluene) and recrystallized frommethanol to obtain 0.72 g of2-(5-trifluoromethylpyridine-2-yl)benzofuran (Yield: 17.7%).

[0115] In a 100 ml-four-necked flask, 25 ml of glycerol was placed andheated at 130-140° C. under stirring and bubbling with nitrogen for 2hours. Then, the glycerol was cooled by standing down to 100° C., and0.70 g (2.66 mM) of 2-(5-trifluoromethylpyridine-2-yl)benzofuran and0.23 g (0.47 mM) of iridium (III) acetylacetonate were added, followedby 7 hours and 10 minutes of heating at 192-230° C. under stirring andnitrogen stream. The reaction product was cooled to room temperature andinjected into 150 ml of 1N-hydrochloric acid to form a precipitate,which was filtered out, washed with water, and dissolved in acetone toremove the insoluble content. The acetone was distilled off underreduced pressure to obtain a residue. The residue was washed withmethanol and purified by silica gel column chromatography with tolueneas the eluent to obtain 0.11 g (yield=23.4%) of red powderytris[2-(benzofuran-2-yl)-5-trifluoromethyl-pyridine-C³,N]iridium (III).

[0116] A toluene solution of the compound exhibited a photoluminescencespectrum showing λmax (maximum emission wavelength)=622 nm and a quantumyield of 0.12.

EXAMPLES 2-10

[0117] Each of luminescence devices having a layer structure shown inFIG. 1B were prepared in the following manner.

[0118] On a 1.1 mm-thick glass substrate (transparent substrate 15), a100 nm-thick film (transparent electrode 14) of ITO (indium tin oxide)was formed by sputtering, followed by patterning to form a stripeelectrode including 100 lines each having a width of 100 nm and aspacing with an adjacent line of 10 nm (i.e., electrode pitch of 110nm).

[0119] On the ITO-formed substrate, three organic layers and two metalelectrode layers shown below were successively formed by vacuum (vapor)deposition using resistance heating in a vacuum chamber (10⁻⁴ Pa).

[0120] Organic layer 1 (hole transport layer 13) (40 nm): α-NPD

[0121] Organic layer 2 (luminescence layer 12) (30 nm): co-depositedfilm of CBP:metal complex (metal coordination compound shown in Table18) (95:5 by weight)

[0122] Organic layer 3 (electron transport layer 16) (30 nm): Alq3

[0123] Metal electrode layer 1 (metal electrode 11) (15 nm): Al-Li alloy(Li=1.8 wt. %)

[0124] Metal electrode layer 2 (metal electrode 11) (100 nm): Al

[0125] The above-deposited metal electrode layers 1 and 2 (Al-Li layerand Al layer) had a stripe electrode pattern including 100 lines eachhaving a width of 100 nm and a spacing of 10 nm (electrode pitch=110 nm)and arranged so that the stripe electrode pattern intersected with thatof the ITO electrode at right angles to form a matrix of pixels eachhaving an effective electrode area of 3 mm² comprising 20 ITO linesbundled together at a lead-out portion and 15 Al (Al-Li) lines bundledtogether at a lead-out portion.

[0126] Each of the thus-prepared luminescence devices was taken out ofthe vacuum chamber and was subjected to a continuous energization(current passage) test in an atmosphere of dry nitrogen gas stream so asto remove device deterioration factors, such as oxygen and moisture(water content).

[0127] The continuous energization test was performed by continuouslyapplying a voltage at a constant current density of 70 mA/cm² to theluminescence device having the ITO (transparent) electrode (as an anode)and the Al (metal) electrode (as a cathode), followed by measurement ofemission luminance (brightness) with time so as to determine a time(luminance half-life) required for decreasing an initial luminance(80-250 cd/m²) to ½ thereof.

[0128] The results are shown in Table 18 appearing hereinafter.

Comparative Example 1

[0129] A comparative luminescence device was prepared and evaluated inthe same manner as in Examples 2-10 except that the Ir complexes (metalcoordination compounds shown in Table 185) was changed toIr-phenylpyrimidine complex (Ir(ppy)₃) shown below.

[0130] The results are also also shown in Table 18 below. TABLE 18 Ex.No. Compound No. Luminance half-life (Hr) Ex. 2 4 800 Ex. 3 10 900 Ex. 431 750 Ex. 5 34 900 Ex. 6 92 800 Ex. 7 115 650 Ex. 8 135 750 Ex. 9 156850 Ex. 10 238 600 Comp. Ex. 1 Ir (ppy)₃ 350

[0131] As is apparent from Table 18, compared with the conventionalluminescence device using Ir(ppy)₃, the luminescence devices using themetal coordination compounds of formula (1) according to the presentinvention provide longer luminance half-lives, thus resulting in an ELdevice having a high durability (luminance stability) based on a goodstability of the metal coordination compound of formula (1) of thepresent invention.

EXAMPLE 11

[0132] A color organic EL display apparatus shown in FIG. 2 was preparedin the following manner.

[0133] An active matrix substrate had a planar structure basicallysimilar to a structure described in U.S. Pat. No. 6,114,715.

[0134] Specifically, on a 1.1 mm-thick glass substrate, top gate-typeTFTs of polycrystalline silicon were formed in an ordinary manner andthereon, a flattening film was formed with contact holes for electricalconnection with a pixel electrode (anode) at respective source regions,thus preparing an active matrix substrate with a TFT circuit.

[0135] On the active matrix substrate, a 700 nm-thick pixel electrode(anode) of ITO having a large work function was formed in a prescribedpattern. On the ITO electrode, prescribed organic layers and a 100nm-thick Al electrode (cathode) were successively formed by vacuumdeposition with a hard mask, followed by patterning to form a matrix ofcolor pixels (128×128 pixels).

[0136] The respective organic layers corresponding to three color pixels(red (R) green (G) and blue (B)) were consisting of the followinglayers.

R Pixel Region

[0137] α-NPD (40 nm)/CBP: Ex. Comp. No. 34 (93:7 by weight) (30 nm)/BCP(20 nm)/Alq 3 (40 nm)

G Pixel Region

[0138] α-NPD (50 nm)/Alq 3 (50 nm)

B Pixel Region

[0139] α-NPD (50 nm)/BCP (20 nm)/Alq 3 (50 nm)

[0140] When the thus-prepared color organic EL display apparatus wasdriven, desired color image data can be displayed stably with good imagequalities.

EXAMPLE 12 Synthesis of Ex. Comp. No. 31

[0141] It is easy to synthesize the following compound in the samemanner as in Example 1 except for using 2-bromopyridine (made by TokyoKasei Kogyo K.K.) instead of 2-chloro-5-trifluoromethylpyridine inExample 1.

[0142] Tris[2-(benzofuran-2-yl)pyridine-C³,N]iridium (III).

EXAMPLE 13 Synthesis of Ex. Comp. No. 32

[0143] It is easy to synthesize the following compound in the samemanner as in Example 1 except for using2-chloro-4-trifluoromethylpyridine (made by Florochem USA) instead of2-chloro-5-trifluoromethylpyridine in Example 1.

[0144] Tris[2-(benzofuran-2-yl)-4-trifluoromethyl-pyridine-C³,N]iridium(III).

EXAMPLE 14 Synthesis of Ex. Comp. No. 33

[0145] It is easy to synthesize the following compound in the samemanner as in Example 1 except for using2-chloro-4,5-bis(trifluoro-methyl)pyridine (made by Oakwood ProductsInc.) instead of 2-chloro-5-trifluoromethylpyridine in Example 1.

[0146] Tris[2-(benzofuran-2-yl)-4,5-bis(trifluoro-methyl)pyridine-C³,N]iridium (III).

EXAMPLE 15 Synthesis of Ex. Comp. No. 35

[0147] It is easy to synthesize the following compound in the samemanner as in Example 16 except for using 4-phenyl-2-bromopyridine (madeby General Intermediates of Canada) instead of2-chloro-5-trifluoromethylpyridine in Example 1.

[0148] Tris[2-(benzofuran-2-yl)-4-pyridine-C³,N]-iridium (III).

EXAMPLE 16 Synthesis of Ex. Comp. No. 36

[0149] It is easy to synthesis the following compound in the same manneras in Example 1 except that 2-(benzofuran-2-yl)-5-bromopyridine wassynthesized from 2,5-dibromopyridine (made by Tokyo Kasei Kogyo K.K.)and 2-benzofuranboronic acid (made by Aldrich Co.) and is reacted with1-naphthylboronic acid (made by Tokyo Kasei Kogyo) to obtain2-(benzofuran-2-yl)-5-(naphthalene-1-yl)pyridine, which is used insteadof 2-(5-trifluoromethylpyridine-2-yl)benzofuran.

[0150]Tris[2-(benzofuran-2-yl)-5-(naphthalene-1-yl)pyridine-C³,N]iridium(III).

EXAMPLE 17 Synthesis of Ex. Comp. No. 42

[0151] It is easy to synthesize the following compound in the samemanner as in Example 16 except for using 2-naphthylboronic acid (made byTokyo Kasei Kogyo K.K.) instead of 1-naphthylboronic acid in Example 16.

[0152] Tris[2-(benzofuran-2-yl)-5-(naphthalene-2-yl)pyridine-C³N]iridium (III).

EXAMPLE 18 Synthesis of Ex. Comp. No. 47

[0153] It is easy to synthesize the following compound in the samemanner as in Example 1 except for reacting 2 equivalent amount of2-benzofuran boronic acid (made by Aldrich Co.) with 2,5-dibromopyridine(made by Tokyo Kasei Kogyo K.K.) to synthesis2,5-bis(benzofuran-2-yl)pyridine, which is used instead of2-(5-trifluoromethylpyridine-2-yl)benzofuran, in Example 1.

[0154] Tris[2,5-bis(benzofuran-2-yl)pyridine-C³,N]iridium (III).

EXAMPLE 19 Synthesis of Ex. Comp. No. 50

[0155] It is easy to synthesis the following compound in the same manneras in Example 1 except that 2-(benzofuran-2-yl)-5-bromopyridine wassynthesized from 2,5-dibromopyridine (made by Tokyo Kasei Kogyo K.K.)and 2-benzofuranboronic acid (made by Aldrich Co.) and is reacted with3-thiopheneboronic acid (made by Aldrich Co.) to obtain2-(benzofuran-2-yl)-5-(thiophene-3-yl)pyridine, which is used instead of2-(5-trifluoromethylpyridine-2-yl)benzofuran.

[0156] Tris[2-(benzofuran-2-yl)-5-(thiophene-3-yl)pyridine—C³,N]iridium(III).

EXAMPLE 20

[0157] An organic EL device shown in FIG. 1C was prepared in thefollowing manner.

[0158] On a 100 nm-thick patterned ITO electrode (anode) formed on a 1.1mm-thick no-alkali glass substrate, a 40 nm-thick charge transport layerof α-NPD was formed by vacuum deposition (10-4 Pa) at a deposition rateof 0.1 nm/sec. On the charge transport layer, a 40 nm-thick luminescencelayer (co-deposited film) of CBP: iridium complex of Ex. Comp. No. 34prepared in Example 1 (97:3 by weight) was formed by co-vacuumdeposition at deposition rates of 0.1 nm/sec (for CBP) and 0.08 nm/sec(for the iridium complex) by controlling heating conditions ofdeposition vessel. On the luminescence layer, a 10 nm-thick excitondiffusion prevention layer of BCP (Bathocuproine) was formed by vacuumdeposition at a deposition rate of 0.1 nm/sec, and or the excitondiffusion prevention layer, a 20 nm-thick electron transport layer ofAlq 3 was formed by vacuum deposition at a deposition rate of 0.1nm/sec. Thereafter, or the electron transport layer, a 150 nm-thickaluminum electrode (cathode) was formed by vacuum deposition at adeposition rate of 1 nm/sec.

[0159] The thus-prepared organic EL device exhibited an EL spectrumshowing λmax=625 nm and luminescent efficiencies of 1.5 lm/W at aluminance of 100 cd/m².

EXAMPLE 21 Synthesis of Ex. Comp. No. 62

[0160]

[0161] In a 2 liter-three-necked flask, 145.8 g (718 mM) of5-bromo-2-hydroxybenzyl alcohol, 246.5 g (718 mM) of triphenylphosphine-HBr, and 730 ml of acetonitrile were placed and refluxed understirring for 3 hours. The reaction liquid was cooled down to roomtemperature to precipitate a crystal of5-bromo-2-hydroxybenzyltriphenylphosphonium bromide (I), which wasrecovered by filtration (Yield: 362.0 g (95.5%)).

[0162] In a I liter-three-necked flask, 50.0 g (94.7 mM) o thephosphonium bromide (I), 31.1 g (104 mM) of 1-nonanoic acid anhydride,450 ml of toluene and 39.6 g (392 mM) of triethylamine were placed andrefluxed under stirring for 6 hours. The reaction liquid was cooled downto room temperature to precipitate a crystal, which was filtered out.The solvent of the filtrate was distilled off under reduced pressure toobtain a residue. The residue was purified by silica gel columnchromatography (eluent: hexane) to a colorless oily product of2-octyl-5-bromobenzofuran (II) (Yield: 25.1 g (85.8%)).

[0163] In a 500 ml-three-necked flask, 19.0 g (61.5 mM) of2-octyl-5-bromobenzofuran (II) and 190 ml of anhydrous tetrahydrofuran(THF) were placed. To the mixture, 45 ml (72.0 mM) of1.6M-n-butyllithium solution in hexane was added dropwise under argonstream at −70° C. or below in 30 min., followed by stirring at thattemperature for 4 hours. To the resultant mixture, a solution of 17.8 g(171 mM) of trimethylborate in 70 ml of anhydrous THF was added dropwiseat −70° C. or below in 20 min., and stirred at that temperature for 2hours. The system was heated up to room temperature and stirred for 17hours. To the reaction mixture, 100 ml of 10%-hydrochloric acid wasadded dropwise, followed by extraction with ether. The organic layer waswashed with water and dried with anhydrous sodium sulfate, followed bydistilling-off of the solvent under reduced pressure to obtain aresidue. The residue was purified by silica gel column chromatography(eluent: hexane/ethyl acetate=4/1) to obtain a white crystal of2-octylbenzofuran-5-boronic acid (III) (Yield: 10.8 g (64.1%)).

[0164] It is easy to synthesize the following compound in the samemanner as in Example 1 except for using 2-octylbenzofuran-5-boronic acid(III) instead of 2-benzofuran boronic acid in Example 1.

[0165] Tris[2-(2-octylbenzofuran-5-yl)pyridine-C³,N]iridium (III).

EXAMPLE 22 Synthesis of Ex. Comp. No. 61

[0166] It is easy to synthesis the following compound in the same manneras in Example 1 except for using, instead of2-(5-trifluoromethylpyridine-2-yl)benzofuran,2-phenyl-5-(5-tifluoromethylpyridine-2-yl)benzofuran synthesized in thesame manner as in Example 21 except that 2-phenyl-5-bromobenzofuran wassynthesized from benzoic acid chloride used instead of 1-nonanoic acidand 2-phenyl-5-(5-trifluoromethyl-pyridine-2-yl)benzofuran wassynthesized from 2-phenyl-5-bromobenzofuran.

[0167] Tris[2-(2-phenylbenzofuran-5-yl)-5-trifluoro-methylpyridine-C³,N]iridium (III).

EXAMPLE 23 Synthesis of Ex. Comp. No. 72

[0168] 4-bromo-2-hydroxybenzyl alcohol (IV) is synthesized from4-aminosalicylic acid (made by Aldrich Co.) in the following reactionscheme, and 4-bromo-2-hydroxybenzyltriphenylphosphon bromide (V) issynthesized in the same manner as in Example 21.

[0169] It is easy to synthesize the following compound in the samemanner as in Example 21 except for using 1-butanoic acid anhydrateinstead of 1-nonanoic acid anhydrate in Example 21.

[0170] Tris[2-(2-propylbenzofuran-6-yl)pyridine-C⁵,N]iridium (III).

[0171] As described above, according to the present invention, the metalcoordination compound of the formula (1) characterized by the benzofuranstructure of the formula (5) as a partial structure is an excellentmaterial which exhibits a high emission quantum efficiency. Theelectroluminescence device (luminescence device) of the presentinvention using, as a luminescent center material, the metalcoordination compound of the formula (1) is an excellent device whichnot only allows high-efficiency luminescence but also retains a highluminance for a long period and shows little deterioration by currentpassage. Further, the display apparatus using the electroluminescencedevice of the present invention exhibits excellent display performances.

What is claimed is:
 1. A metal coordination compound represented byformula (1) below: ML_(m)L′_(n)  (1),wherein M is a metal atom of Ir,Pt, Rh or Pd; L and L′ are mutually different bidentate ligands; m is 1,2 or 3 and n is 0, 1 or 2 with the proviso that m+n is 2 or 3; a partialstructure MLm is represented by formula (2) shown below and a partialstructure ML′_(n) is represented by formula (3) or (4) shown below:

 wherein CyN1 and CyN2 are each cyclic group capable of having asubstituent, including a nitrogen atom and bonded to the metal atom Mvia the nitrogen atom; CyC1 and CyC2 are each cyclic group capable ofhaving a substituent, including a carbon atom and bonded to the metalatom M via the carbon atom with the proviso that the cyclic group CyN1and the cyclic group CyC1 are bonded to each other via a covalent bondand the cyclic group CyN2 and the cyclic group CyC2 are bonded to eachother via covalent bond; the optional substituent of the cyclic groupsis selected from a halogen atom, cyano group, a nitro group, atrialkylsilyl group of which the alkyl groups are independently a linearor branched alkyl group having 1 to 8 carbon atoms, a linear or branchedalkyl group having 1 to 20 carbon atoms of which the alkyl group caninclude one or non-neighboring two or more methylene groups that can bereplaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C—, and thealkyl group can include a hydrogen atom that can be optionally replacedwith a fluorine atom, or an aromatic group capable of having asubstituent (that is a halogen atom, a cyano atom, a nitro atom, alinear or branched alkyl group having 1 to 20 carbon atoms of which thealkyl group can include one or non-neighboring two or more methylenegroups that can be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH—or —C≡C—, and the alkyl group can include a hydrogen atom that can beoptionally replaced with a fluorine atom); E and G are independently alinear or branched alkyl group having 1 to 20 carbon atoms of which thealkyl group can include a hydrogen atom that can be optionally replacedwith a fluorine atom, or an aromatic group capable of having asubstituent (that is a halogen atom, a cyano atom, a nitro atom, atrialkylsilyl group of which the alkyl groups are independently a linearor branched alkyl group having 1-8 carbon atoms, a linear or branchedalkyl group having 1 to 20 carbon atoms of which the alkyl group caninclude one or non-neighboring two or more methylene groups that can bereplaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C—, and thealkyl group can include a hydrogen atom that can be optionally replacedwith a fluorine atom; and at least one of the optional substituent(s) ofthe cyclic groups, and the cyclic groups CyC1 and CyC2 includes abenzofuran structure capable of having a substituent represented by thefollowing formula (5):

 wherein the benzofuran structure of the formula (5) is bonded to CyN1,CyN2, CyC1 or CyC2 via a single bond at any one of 2- to 7-positionswhen the benzofuran structure is the optional substituent(s) of thecyclic groups, and the benzofuran structure of the formula (5) is bondedto CyN1 or CyN2 via a single bond at any one of 2- to 7-positions andbonded to the metal atom M via a single bond at any one of 2- to7-positions when the benzofuran structure is CyC1 or CyC2; the optionalsubstituent of the benzofuran structure of the formula (5) is selectedfrom a halogen atom, cyano group, a nitro group, a trialkylsilyl groupof which the alkyl groups are independently a linear or branched alkylgroup having 1 to 8 carbon atoms, a linear or branched alkyl grouphaving 1 to 20 carbon atoms of which the alkyl group can include one ornon-neighboring two or more methylene groups that can be replaced with—O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C—, and the alkyl groupcan include a hydrogen atom that can be optionally replaced with afluorine atom, or an aromatic group capable of having a substituent(that is a halogen atom, a cyano atom, a nitro atom, a linear orbranched alkyl group having 1 to 20 carbon atoms of which the alkylgroup can include one or non-neighboring two or more methylene groupsthat can be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or—C≡C—, and the alkyl group can include a hydrogen atom that can beoptionally replaced with a fluorine atom) with the proviso that anadjacent pair of substituents located at 4- to 7-positions of thebenzofuran structure of the formula (5) can be bonded to form a cyclicstructure.
 2. A metal coordination compound according to claim 1,wherein n is 0 in the formula (1).
 3. A metal coordination compoundaccording to claim 1, including a partial structure ML′_(n) representedby the formula (3) in the formula (1).
 4. A metal coordination compoundaccording to claim 1, including a partial structure ML′_(n) representedby the formula (4) in the formula (1).
 5. A metal coordination compoundaccording to claim 1, wherein the cyclic groups CyC1 and CyC2 areindependently selected from phenyl group, thienyl group, thianaphthylgroup, naphthyl group, pyrenyl group, 9-fluorenonyl group, fluorenylgroup, dibenzofuranyl group, dibenzothienyl group, carbazolyl group, orbenzofuranyl group, as an aromatic cyclic group capable of having asubstituent with the proviso that the aromatic cyclic group can includeone or two CH groups that can be replaced with a nitrogen atom.
 6. Ametal coordination compound according to claim 5, wherein the cyclicgroups CyC1 and Cy2 are independently phenyl group or benzofuranylgroup.
 7. A metal coordination compound according to claim 1, whereinthe cyclic groups CyN1 and CyN2 are independently selected from pyridylgroup, pyridazinyl group, and pyrimidinyl group, as an aromatic cyclicgroup capable of having a substituent.
 8. A metal coordination compoundaccording to claim 7, wherein the aromatic cyclic group is pyridylgroup.
 9. A metal coordination compound according to claim 1, whereinthe cyclic groups CyN1, CyN2, CyC1 and CyC2 are independentlynon-substituted, or have a substituent selected from a halogen atom anda linear or branched alkyl group having 1 to 20 carbon atoms {of whichthe alkyl group can include one or non-neighboring two or more methylenegroups that can be replaced with —O—, —S—, —CO—, —CH═CH—, —C≡C—, or adivalent aromatic group capable of having a substituent (that is ahalogen atom or a linear or branched alkyl group having 1 to 20 carbonatoms (of which the alkyl group can include one or non-neighboring twoor more methylene groups that can be replaced with —O—, and the alkylgroup can include a hydrogen atom that can be optionally replaced with afluorine atom)), and the alkyl group can include a hydrogen atom thatcan be optionally replaced with a fluorine atom}.
 10. A metalcoordination compound according to claim 1, wherein M in the formula (1)is iridium.
 11. A metal coordination compound according to claim 1,which is represented by the following formula (6) or (7):

wherein R₁, R₂, R₃, R′₃ and R₄ are independently a hydrogen atom; afluorine atom; a linear or branched alkyl group of formula:C_(n)H_(2n+1)— in which n is an integer of 1-20, the alkyl group caninclude one or non-neighboring two or more methylene groups that can bereplaced with —O— and also can include a hydrogen atom that can beoptionally replaced with a fluorine atom; a phenyl group capable ofhaving a substituent; or a benzofuranyl group capable of having asubstituent; the optional substituent of phenyl group and benzofuranylgroup is a fluorine atom or a linear or branched alkyl group of formula:C_(n)H_(2n+1)— in which n is an integer of 1-20, the alkyl group caninclude one or non-neighboring two or more methylene groups that can bereplaced with —O— and also can include a hydrogen atom that can beoptionally replaced with a fluorine atom.
 12. An electroluminescencedevice, comprising: a pair of electrodes disposed on a substrate, and aluminescence unit comprising at least one organic compound disposedbetween the electrodes, wherein the organic compound comprises a metalcoordination compound represented by the formula (1) in claim
 1. 13. Anelectroluminescence device according to claim 12 wherein a voltage isapplied between the electrodes to emit phosphorescence.
 14. A picturedisplay apparatus, comprising an electroluminescence device according toclaim 12, and a means for supplying electric signals to theelectroluminescence device.